Mar 16 , 2021
Immunoglobulin D (IgD) is an antibody isotype that is found primarily on mature B cells as part of the B cell receptor (BCR) complex. Clustering of the BCR due to antigen binding leads to activation of B cells that can result in a number of outcomes including proliferation, differentiation or tolerance. The ability to activate B cells in a research setting using polyclonal antisera recognizing anti-IgD is useful for the study of B cell function (Finkelman, et al., 1985; Nguyen, et al., 2014). Anti-IgD is particularly suited for this application because soluble IgD is present in extremely low levels (<0.25% of total immunoglobulin) and will not interfere with B cell activation in a whole blood-based or in vivo setting. (In contrast, high levels of circulating IgM will typically block B cell activation by anti-IgM in whole blood.) Such a methodology can be used to rapidly test the efficacy of B cell inhibitory agents in a cellular or in vivo context (Coffey, et al., 2012).
MD Bioproducts offers an antiserum to mouse IgD to stimulate the B cell activation.
D cross-linking on B cells is an ideal model for the assessment of acute polyclonal B cell activation across multiple strains of mice. Following anti-IgD injection (100µl/mouse, i.v.), peripheral B cells are rapidly activated as evidenced by up-regulation of CD86 and CD69. Activated B cells will secrete effector cytokines (IL-4) and acquire effector function (secretion of IgE antibodies) within 5-7 days. Anti-mouse IgD can also be used to induce functional B cells in vitro. This model system is ideal for specific examination of key pathways and players in the functional activation of peripheral B cells in vivo.
B cells in the blood of BALB/c mice were gated on CD19 and B220 dual expression using flow cytometry. B cell activation was determined by up-regulation of activation marker CD86. A greater than 3-fold increase in the percent of CD86+ cells was observed within 3 hours of anti-IgD antiserum injection.